Apple made a smattering of notable iOS announcements yesterday one of which was significant improvements to its camera app. While we’ll have to wait for the next-gen iPhone for some actual camera hardware upgrades, the software enhancements Apple introduced yesterday are quite compelling. Notably, Scott Forstall yesterday pointed out that the iPhone 4 is the second most popular camera on Flicr and the most popular camera phone period.

In any event, below is a run down of some the cool new features in the iOS 5 camera app.

First off, Apple made access to the camera app a whole lot easier by making it accessible via the lockscreen. There’s nothing worse than seeing a great photo opportunity go to waste because you’re fiddling around trying to unlock your iPhone, open up the camera app, adjust to focus, and then take a shot. Now, with iOS 5, users can double tap the home button from the lockscreen where they’ll be immediately whisked away to the camera app. This is huge and a much welcome change.

Second, iOS 5 users can now take a photo by pressing the volume-up button on their iPhone instead of having to rely exclusively on the on-screen shutter button. This is a usability issue and should make it much more convenient and natural to take photos with the iPhone than its ever been before. Of course, we should point that Apple had previously removed the Camera+ app for enabling such functionality on the down low. Well, it’s back, and we can’t complain.

Third, Apple has introduced new editing features to the camera app like cropping, red eye reduction and one-click photo enhancements which should be familiar to anyone who’s used iPhoto before.

Further, Apple in iOS 5 has implemented new (and optional) gridlines in the camera app to help users compose their shots along with the ability to pinch to zoom while taking a shot. Lastly, the upgraded app enables users to lock autofocus and autoexposure with just one tap.